The present invention relates to the manufacture of rod-shaped smokers' products in general, and more particularly to improvements in means for recovering reusable and/or non-reusable tobacco particles which leave their intended path during transport through one or more machines for the making of plain or filter tipped cigarettes, cigars or cigarillos.
It is already known to combine a single tobacco processing machine or a group of such machines with a segregating device which serves to remove tobacco particles (particularly reusable tobacco particles) for renewed processing, especially to remove tobacco particles and/or other solid particles from one or more air streams which are used in such machines to attract or transport tobacco particles, wrapped or unwrapped rod-like fillers consisting of tobacco, and/or fillers and filter rod sections. Tobacco particles which escape from their intended path are often small. Thus, and referring by way of example to the manufacture of plain or filter cigarettes, smaller shreds of tobacco leaves whose size may vary within a wide range and includes sizes which are characteristic of tobacco dust are likely to escape during the forming of continuous tobacco filter, during wrapping of the filler in cigarette paper, during severing of the resulting cigarette rod into discrete plain cigarettes (wrapped fillers of finite length), during transport of plain cigarettes into a filter cigarette making machine, during assembly of plain cigarettes with filter rod sections to form filter cigarettes, during testing of filter cigarettes, and during further transport of tested cigarettes to a packing machine. Many units of such machines operate with suction, e.g., one or more rotary drum-shaped conveyors may be provided with flutes which communicate with ports connected to a suction generating device to retain wrapped fillers, filter rod sections and/or filter cigarettes during transport from station to station. Smaller solids which escape during manipulation of comminuted tobacco leaves, unwrapped fillers, wrapped fillers and filter cigarettes often consist of quartz.
All such units of a cigarette making or filter cigarette making machine (or of a complete production line including the just mentioned machines) which operate with suction air are normally connected to a single suction generating device (e.g., a large fan). In many presently known machines or production lines a single device for segregation of tobacco particles and/or other solids which escape during processing of tobacco is installed in the conduit which is connected with the outlet of the suction generating device. The purpose of the segregating device is to prevent the escape of tobacco and/or quartz dust into the atmosphere. It has been found that a single segregating device for solid particles which escape in a cigarette making machine does not suffice to collect all solid particles and that such device is not suited for recovery of reusable tobacco particles except by hand. Also, it has been found that the presently known segregating devices which are used in connection with filter cigarette making machines are quite unsatisfactory, especially as concerns the percentage of recovered solids and also as regards the ease of recycling reusable tobacco particles. Still further, the presently known segregating devices are very sensitive in that they are likely to be clogged with solid particles after a relatively short period of use. The cleaning of or replacement of expandable parts in such segregating devices is time-consuming and necessitates lengthy interruptions in the operation of respectie machines.